Floatless carburetor



M. M EN N ESSON FLOATLES S CARBURETOR Dec. 14, 1937.

Filednec. 28, 19.56

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I f Patented Dec.l 14, 1937 UNITED STATES PATENT OFFICE V'FLOATLESSCARBURETOR Man-e1 Menn'esson, Neuilly-subsane, France,

assignor to "Socit Anonyme Solex NeuillysurSeine,vFrance, a society ofFrance y Application neember 2s, 1936, 'serial No. 117,953 In FranceJanuary 3, 1936 14 claims.

, buretors of the type comprising a chamber subthe well is pierced witha desired number of stantially 'independent of the pressure in theinduction pipe downstream of the throttle in which the primary mixture-of fuel and air is effected, have combined therewith a pump to supply`the fuel to the said chamber, the delivery from which pump isproportional to the speed of the engine.

The `fuel is supplied to a chamber communicating, on the one hand, by acalibrated discharge orifice, lpreferably controllable by hand orautomatically, with the fuelv feed reservoir and, on the other hand,with the primary mixing chamber by an orifice of which the -free sectionis adapted to be modified by hand or automatically.

The invention further consists, apart from this `principal arrangement,in certain other arrangements, which are preferably utilized at the sametime and which will be referred-to more explicitly hereafter,particularly in a second arrangement, consisting in assuring theautomatic regulation of the fuelsupply oriiice in the primary mixingchamber, of carburetors of the kind in question, by the intermediary ofmeans actuated by variable temporary conditions, such as the pressureexisting downstream of the throttling member for the gases, thetemperature, density or pressure of vthe atmospheric air, the supply tothe engine, and the like, considered together or separately; and in athird arrangement, consisting in submittingthe air, admitted into theprimary mixing chamber of the carburetors of the kind in question, to apreliminary to the accompanying drawing, which is given by way ofexample and in whichz- Fig. 1 shows, in `diagrammatic vertical section,a carburetor constructed according to the invention.

Fig. 2 shows, similarly,a part of a carburetor constructed according toa variation of the preceding arrangement. y

In the inlet pipe I, with throttle valve 2 of the carburetor, there islocated a chamber 3 of which This chamber is located between the holes4.

preferably,

throttle valve 2 and the engine and, in a Venturi sleeve 5.

The chamber 3 is made to communicate with -the atmospheric air or theprincipal air inlet of the carburetor by a conduit 6 of relatively greattransverse section. There are given to the conduit 6 and to the holes 4relative dimensions 5 such that, in spite ofthe chamber 3 being locatedin the inlet pipe I downstreamward of thethrottle valve, the pressureexisting inthe interior of the said chamber 3 is practically independentof that existing in the said pipe l. 10

The chamber 3 is supplied with fuel by the intermediary of a pump 1 ofwhich the type chosen is such that its delivery is proportional to thespeed of the engine, for example a volumetric or. centrifugal pump. TheApump is made l5 to deliver by a conduit 8 into a chamber 9 which,itself, communicates with the chamber 3 by a calibrated orifice IIl ofwhich the free section can be modified by the intermediary of a needlevalve II or the like controlled by hand or auto- 20 matically by meansdescribed hereafter.

The chamber 9 communicates, on the other hand, by a calibrated orificeI2, of which the section is preferably regulatable by the intermediaryof a needle valve I3 or the like, with a conduit I4 25 to return thefuel, delivered in excess by the pump 1, to the reservoir I5. Thedisplacement of the needle valve I3 can be obtained by hand control orby automatic means which are a function of the pressure, of thetemperature, of the density of the inlet air or of the mixture admittedto the engine, utilized Separately or in combination.

The needle valve II, which has an appropriate prole to regulate the freesection of the orifice l0 and consequently the richness of the mixture,can be displaced, byv hand or by an automatic control, as a function ofcertain conditions of operation of the engine, such as the pressureexisting downstream of the throttle valve 2, the 40 degree of supply tothe engine or as a function of certain temporary exterior conditionssuch as the pressure, density or temperature of the atmospheric air.

In order that the eiect of these variable factors can modify theposition of the needle valve Il or the like, these factors are made toact on auxiliary means such as manometric, barometric. thermometricor-other devices adapted to cause the automatic displacement of the saidneedle valve. i

In Figs. 1 and 2 is shown, by way of example, that there is-made tointervene, as active factor, the pressure existing in the suction pipeof the engine downstream of the throttling member 2,

In Fig. 1 this pressure acts on a manometric capsule I6 integral withthe needle valve and of which the position with respect to the body ofthe carburetor is regulatable by the intermediary of a screw i1. As aresult thereof if the position ofthe capsule I8 is regulated, at thesame time the initial position of the needle valve is modified. Thecapsule I6 is located in a chamber I8 which is connected by a conduit I9to the suction pipe I downstream of the throttle valve 2.

In Fig. 2 the needle valve is connected to a diaphragm ||51 separating achamber into two compartments of which one, designated by.2il and whichis located on the side of the needle valve is connected by a conduit I9to the suction pipe I. The second compartment 2| communicates by acalibrated orifice 22 with a hermetically closed receptacle 23containing a gas at a desired pressure.1 Advantageously the pressure ofthe gas is caused to act on .the diaphragm |61 by the intermediary of aliquid 24 in such a way as to absorb the displacements of smallamplitude of the diaphragm |61 under the effect of the depression actingin the compartment 2li.

In Fig. 1 there have also been shown means for heating the air admittedby the conduit 6 into the primary mixing chamber 3. To this end at leasta part of the said conduit is located in a chamber 25 in which there iscaused to pass a current of hot fluid, for example a part of the exhaustgases of the engine, or the like. -In this Way there is avoided, forexample, the phenomenon of freezing-up which could be produced at theplace of the holes t, through which the chamber 3 deliversthe'combustible mixture.

The arrangement, such as described, functions as follows.

When the engine turns slowly, the pump i itself turns slowly, andconsequently delivers little fuel. Moreover, as the depression is greatin the inlet pipe downstream of the throttle valve 2 (closed in thiscase), the needle valve i by being displaced by the capsule I6 (Fig. 1)or the diaphragm |61 (Fig. 2) obturates to the maximum the orince |0.The section of this orifice is calculated or regulated in such a way asto allow to pass the quantity of fuel strictly necessary for permittingthe engine to maintain its slow-running speed.

Owing to the relative sections of the holes 4 and of the conduit 6 thereexists practically no depression in the chamber 3. In this way thedelivery of fuel by the orifice lli is never caused directly by theeffect of this depression.

If the throttling member 2 is opened, the admission of air is increased,on the one hand, and

the depression in the inlet pipe diminished, on the other hand. As aresult thereof, the capsule I6 or the diaphragm |61 is deformed in sucha way as to increase the section of the orifice I0, which thus allows alarger quantity of fuel to escape.

As the speed of the engine increases, the delivery of the pump 'iequally increases and the profile of the needle valve is calculated in'discharge pressure equally increases and to regulate this pressure oneacts on the passage section of the orifice I2 which permits the returnof the excess of fuel to the reservoir I5.

If, on the contrary, the throttling member 2 is closed, the depressionincreases, immediately, in the suction pipe |y in such a way that thecapsule I6 or the diaphragm |61 is deformed forcing the needle valvetowards its closing position. The delivery of fuel decreases inconsequence, which causes a diminution of the speed of rotation of theengine and of the pump down to the slow-running speed.

It follows from the above that there is obtained a oatless carburetor ofwhich the operation is assured for all the positions that one can be ledto give the engine on which it is fitted and which permits of obtaininga regular and rational feeding for all conditions of operation of thesaid engine.

What I claim is:

1. A oatless arbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in said suction pipe, afuelair mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having a largeeffective area and communicating with said mixing chamber, a fuelreservoir, a feed chamber communicating withl said mixing chamber, arotary pump connected to said reservoir and driven by said engine fordelivering fuel to said feed chamber, a discharge orifice connectingsaid feed and mixing chambers, and conduit means connecting said feedchamber to said fuel reservoir.

2. A fioatless carbureting system such as claimed in claim 1 comprisingmeans for regulating the section of said conduit means.

3. A oatless carbureting system such as claimed in'claim l comprisingmeans, regulatable by hand, for controlling the section of said-discharge orifice for the supply of fuel in said mixing chamber.

4. A oatless carbureting system such as claimed in claim 1 comprisingmeans, regulatable automatically, for controlling the section of saiddischarge orifice for the supply of fuel in said mixing chamber.

5. A iioatless carbureting system such as claimed in claim 1 comprisingmeans, regulatable automatically by variable temporary conditions whichare a function of the working of said engine, for controlling thesection of said discharge orifice for the supply of fuel to said mixingchamber.

6. A floatless carbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in said suction pipe, afuelair mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having a largeeecti-ve area and communicating with said mixing chamber, means forheating the air admitted in said air inlet means, a fuel reservoir, afeed chamber communicating with said mixing cham.

ber, a rotary pump connected to said reservoir and driven by said enginefor delivering fuel to said feed chamber, a discharge orifice connectingsaid feed and mixing chambers, and conduit means connecting said feedchamber to said fuel reservoir.

7. A oatless carbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in said suction pipe, afuelair mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having a largeeffective area and communicating with said mixing chamber, means forheating the-air admitted in said air inlet means, said heating meanscom-- prising a source of hot uid, a chamber surrounding a part of saidair inlet means and heatedby a current of hot iiuid supplied by saidsource, a fuel reservoir, a feed chamber communicating with said mixingchamber, a rotary pump connected to saidreservoir and driven by saidengine for delivering fuel to said feed chamber, a discharge orificeconnecting said feed andv mixing chambers, and conduit means connectingsaid. feed chamber to said fuel reservoir.

8. -A floatless carbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in'said suction pipe, afuelair mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having'a largeeffective area and communicating with said mixing chamber, means forheating the air admitted in said air inlet means, said heating meanscom'- prising a source lof hot iiuid, a chamber surrounding a part ofsaid air inlet means and heated by a current of the exhaust gases ofsaid engine and supplied by said source, a fuel reservoir, a feedchamber communicating with said mixing chamber, a rotary pump connectedto said reservoir and driven .by said engine for delivering fuel to saidfeed chamber, a discharge orifice connecting said -feed and mixingchambers, and conduit means connecting ,said feed chamber to said fuelreservoir.

9. A floatless carbureting system for an internal combustion enginecomprising a suction pipe, a' throttling member in said suction pipe, afuelair mixing chamber communicating with said suction pipe through apassage having a small effective area, airvinlet means having a largeeffective area and communicating with said mixing chamber, a fuelreservoir, a feed chamber communicating with said mixing chamber, arotary pump connected to said reservoir and driven by said engine fordelivering fuel to said feed chamber, a discharge orifice connectingsaid,

feed and mixing chambers, means for regulating the section of saiddischarge orifice, a closed chamber communicating with said suction pipedownstream of said throttling member, a pressure responsive memberlocated in said closed chamber and means for connecting said pressureresponsive member to said means for regulating the section of saiddischarge orifice, and conduit means connecting said feed chamber tosaid fuel reservoir.

10. A fioatless carbureting system for an internal` combustion enginecomprising a suction pipe, a `throttling member in said suction pipe, afuel-air mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having ,a large.effective area and communicating with said mixing chamber fuelreservoir, a feed chamber communicating with said mixing chamber, a

rotary pump connected to said reservoir and` driven by said engine fordelivering fuel to said feed chamber, a discharge orifice connectingsaid feed and mixing chambers, means for regulating the section of saiddischarge orifice, a chamber communicating with the suction pipedownstreamward of said throttling member, a pressure responsive memberlocated in said chamber and means for connecting said pressureresponsive member to said means for regulating the section of saiddischarge orifice, and conduit by said engine for delivering fuel tosaid feed chamber, a discharge orice connecting said feed and mixingchambers, means for regulating the section of saiddischarge orifice, aclosed chamber communicating with said suction pipe downstream of saidthrottling member, a pressure responsive member located in said yclosedchamber and means vfor connecting said pressure responsive member tosaid means for regulating the section of said discharge orifice, meansfor regulat-` ing the initial position of said pressure responsivemember, and conduit means connecting said feed chamber to said fuelreservoir.

12. A iioatless carbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in said suction pipe, afuel-air mixing chamber communicating with said suction pipe through apassage having a small effective area, air inlet means having a largeeffective area and communicating with said mixing chamber, a fuelreservoir, a feed chamber communicating with said mixing chamber, arotary pump connected to said reservoir and driven by said engine fordelivering fuel to said feed' chamber, a discharge orifice connectingsaid feed and mixing chambers, means for regulating the section of saiddischarge orifice. a closed chamber communicating with said suction pipedownstream of said throttling member, a' manometric capsule located insaid closed chamber and means for connecting said manometric capsule tosaid means for regulating the section of said discharge' orifice, andconduit means` connecting said feed chamber to said fuel reservoir.

13. A iioatless carbureting system for an interna] combustion enginecomprising a suction pipe, a throttling member in said suction pipe, afuel-air mixing chamberv communicating with said suction pipe through apassage having a small effective area, air inlet means having a largeeffective area and communicating with said mixing chamber, a fuelreservoir, a feed chamber communicating with said mixing chamber, arotary pump connected to said reservoir and driven by said engine fordelivering fuel to said .feed

' chamber, a discharge orifice connecting said feed and mixing chambers,means for regulating the section of said discharge orice, a closedchamber, a membrane subdividing said chamber in two compartments, aconnection between said membrane and said means for regulating thesection of said discharge orifice, conduit means connecting said suctionpipe with that of said compartments which, by a decrease of pressure,provokes the deformation of said membrane in the sense of a decrease ofthe section of said discharge orifice,

pressure producing means acting in the other compartment onsaid'membrane, and conduit means connecting 'said-feed chamber to saidfuel reservoir.

14. A fioatless carbureting system for an internal combustion enginecomprising a suction pipe, a throttling member in said suction pipe, a

compartments, a connection between said membrane and said means forregulating the section of said discharge oritlce, conduit meansconnecting said suction pipe with that of said compartments which, by adecrease o! pressure, provokes the deformation of said membrane in thesense of a decrease of the section of said discharge orice, fluidpressure producing means acting in the other compartment on saidmembrane, and conduit means connecting said feed chamber to said 10 fuelreservoir.

MARCEL MENN'ESSON.

